含N’N-二乙基硫脲添加剂的微电铸工艺金属铜填洞机理

为了研究含N’N-二乙基硫脲添加剂的微电铸工艺金属铜填洞机理,采用线性伏安法、循环电压电流溶出法(CVS)、扫描电镜(SEM)以及XRD测量法研究了N’N-二乙基硫脲对微电铸工艺电化学行为的影响,并借助塔菲尔方程,研究了微电铸铜反应过程中的电极动力学参数。结果表明,当微电铸铜工艺中加入N’N-二乙基硫脲添加剂时,产生活性极化,提高了铜离子还原时所需的活化能,金属离子的放电速度从2.221 4 mA/cm2降低到约0.076 mA/cm2,从而增加了反应时的过电位,促使电极表面晶核成型速度增加,晶体成长速度由2.57μm/min降低到约0.17μm/min,铜离子的平滑能力提高约50%,有效地减小了微电铸时的边沿效应,使金属铜具有良好的填充微型孔洞的能力。本实验通过微电铸工艺成功地将金属铜填充入宽为10μm,深宽比为4∶1的微型凹槽中,且镀层内没有空洞、空隙及细缝等缺陷。

Research progress of magnesium anodes and their applications in chemical power sources

Magnesium is a promising metal used as anodes for chemical power sources. This metal could theoretically provide negative discharge potential and exhibit large capacity during the discharge process. However, when the magnesium anode is adopted for practical applications, several issues, such as the discharge products adhered to the electrode surface, the self-discharge occurring on the anode material, and the detachment of metallic particles, adversely affect its inherently good discharge performance. In this work, the types of chemical power sources using magnesium as anodes were elaborated, and the approaches to enhance its anode performance were analyzed.

Regeneration of activated carbon adsorbed EDTA by electrochemical method

Activated carbon after saturated adsorption of EDTA was used as particle electrode in a three-dimensional electrode reactor to treat EDTA-containing wastewater.Electrochemical method was used to regenerate activated carbon after many times of electrolysis.Based on the analysis of infrared spectra of activated carbon after adsorption and repeated electrolysis,EDTA was degraded into glycine,and then non-catalytic activated associated complex was formed with N—H bond on the activated carbon.The catalytic ability of the activated carbon vanished and the EDTA degradation efficiency was dropped.Activated carbon could be effectively regenerated by electrochemical method in the three-dimensional reactor.Effects of electric current,conductivity and pH on activated carbon regeneration were investigated,and the optimum conditions were concluded as follows：100-300 mA of current intensity,1.39 mS/cm of electric conductivity,60 min of electrolysis time and pH 6.0-8.0.Under the optimized conditions,the activity of the activated carbon can be recovered and the residual total organic carbon（TOC） was below 10 mg/L（the initial TOC was 200 mg/L） in the three-dimensional electrode reactor.

Influence of the Dosage of Surfactant on the Electrorheological Behaviors of Fluids

To investigate the influence of surface characteristics of particles on electrorheological (ER) fluids, water free complex strontium titanate particles were synthesized through the sol gel technique and different mass fraction of the surfactant was doped in particles and dispersed in silicon oil. The test shows that surface characteristics of particles have great influence on the behavior of ER fluids. Surface tension, surface polarity and interfacial polarization are strongly related to the surface status of the dispersed particles.

Hyperpolarization-activated Cyclic nucleotide-gated Channel and Cardiac Biological Pacemaker:Part Ⅱ

Abstract Hyperpolarization-activated cyclic-nucleotide-gated ( HCN) channels in the heart modulate cardiac automaticity via the hyperpolarization-activated cation current (named If, Ih, or Iq). Recent studies have unveiled the molecular identity of HCN (HCN 1-4) channels. HCN isoforms are unevenly expressed in the heart, even in the sinoatrial node. Features of HCN currents have been characterized in cardiac and other types of cells or in cell lines transfected with the HCN isoforms. The factors modulating Ih and the physiological significance of HCN channels in the heart have been extensively investigated in recent years. The hypothesis for transplanting and/or creating biological pacemakers to replace diseased sinoatrial and/or atrioventricular nodes has been postulated and tested in animal models. Local overexpression of HCN2 channels in the left atrium or in the left conductive bundle branch of the left ventricle via gene delivery induced significant Ih and escape rhythms during vagal stimulation in canines. In addition, implantation of human mesenchymal stem cells with overexpression of HCN2 channels to the canine left ventricular wall was associated with formation of spontaneous escape rhythms of left-sided origin during vagal-stimulation-induced sinus arrest. This preliminary data suggest that the use of HCN channels may hold great promise in the development of biological pacemakers.

One-step fabrication of TiO2/graphene hybrid mesoporous film with enhanced photocatalytic activity and photovoltaic performance

We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.

Comparative investigation on spindle behavior and MPF activity changes during oocyte maturation between gynogenetic and amphimictic crucian carp

The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp. MPF activity was measured by using histone H1 as phosphorylation substrate. There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes, but there existed some subtle difference between them. The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp. It was suggested that the difference may be related to the spindle behavior changes, such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.

Preparation and electrochemical characterization of activated carbons by chemical-physical activation

A process was proposed based on the combination of chemical and physical activation for the production of activated carbons used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m2/g and 0.308 4 cm3/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance.

Electrochemical CO2 Reduction on Pd-Modified Cu Foil

Bimetallic catalysts can improve CO2 reduction efficiency via the combined properties of two metals.CuPd shows enhanced CO2 reduction activity compared to copper alone.Using differential electrochemical mass spectrometry(DEMS)and electrochemical infrared(IR)spectroscopy,volatile products and adsorbed intermediates were measured during CO2 and CO reduction on Cu and CuPd.The IR band corresponding to adsorbed CO appears 300 mV more positive on CuPd than that on Cu,indicating acceleration of CO2 reduction to CO.Electrochemical IR spectroscopy measurements in CO-saturated solutions reveal similar potentials for CO adsorption and CO3^2-desorption on CuPd and Cu,indicating that CO adsorption is controlled by desorption of CO3^2-.DEMS measurements carried out during CO reduction at both electrodes showed that the onset potential for reduction of CO to CH4 and CH3OH on CuPd is about 200 mV more positive than that on Cu.We attribute these improvements to interaction of Cu and Pd,which shifts the d-band center of the Cu sites.

Study on Activated Carbon for Electrode Material

Activated carbon （AC） was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that： Supercapacitors based on the sample AC-3 have low Equivalent series resistanceb （ESR） and excellent power property.

Analysis of I-V Thermal Characteristic on GaN-based p-i-n Ultraviolet Detector

The I-V characteristic of GaN-based p-i-n ultraviolet detector is presented. It is measured at different temperatures and analyzed with changing temperature. The ideality factor of the device is 2.09 at room temperature. The maximum ideality factor is 2.14 at 100 ℃, which declines above 100 ℃, and the minimum ideality factor is 1.26 at 300 ℃. The coefficient of forward voltage vs. temperature is -1.97 mV/℃ with a forward current of 1 mA. Based on double injection model, the deep lying impurity activation energy in the i-region is 0.1 343 eV.

Effect of Additives on the Performance of Lead Acid Batteries

Effect of titanium dioxide （TiO2） and carbon additives in the respective positive and negative material properties and the influence on the performance of the battery were investigated. The electrode samples were characterized by BET （Brunauer Emmett Teller）, XRD （X-ray diffractometer）, SEM （scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） to understand the surface area, phase, structure, morphology and electrical conductivity of the respective electrode material. The surface area was obtained as 2.312 m2＂g＂l and 0.892 m2＂g＂1, respectively for 12% of activated carbon in the expander of negative and 0.70% of TiO2 （Titanium dioxide） in the PAM （positive active material）. The structural analysis reveals an increase in the tetrabasic lead sulfate and also evidenced by well grown crystals in the PAM with the TiO2, respectively obtained by XRD and SEM techniques. The impedance spectra analysis shows an increase of electrical conductivity of negative active mass with temperature. The battery results showing two fold enhancements in the charge acceptance were attributed to the high surface area activated carbon in the NAM （negative active material）. The materials properties of electrodes and their influence on the battery performance were discussed.

Formation mechanism of electroless plating nickel-based composite coating on highly active rare earth magnesium alloys and its corrosion resistance and adhesion performance

The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.

N′,N′-二乙基硫脲添加剂对铜微沉积工艺电化学行为的影响

为了研究N',N'-二乙基硫脲添加剂在微沉积工艺中对铜金属孔洞填充能力的影响,采用线性伏安法(LSV)、循环伏安法(CV)、SEM测量法分析比较了无添加剂、含硫脲和含N',N'-二乙基硫脲添加剂时微沉积铜工艺中的电化学行为,并借助塔菲尔方程,分析比较此三种情况下电镀反应过程中的电极动力学参数.结果显示:当铜微沉积工艺中加入N',N'-二乙基硫脲添加剂时,产生活性极化,该活性极化效应降低铜离子的放电速度,抑制孔洞边缘部分沉积较快区域的过快生长;同时活性极化提高,将导致成核点的增加,沉积膜的晶粒较小,镀膜也较平滑细致,实验测得铜离子的平滑能力比没有添加剂时提高约50%.最后通过微沉积工艺成功地将金属铜填充入宽为10μm,深宽比为4∶1的微型凹槽中,且镀层内没有空洞、空隙以及细缝等缺陷.

一个先天性指(趾)畸形家系的基因突变分析

目的 对一个指(趾)畸形家系进行基因突变分析,探讨其遗传学病因.方法 收集该家系的临床资料,采集家系成员的外周血样,提取基因组DNA,应用PCR产物直接测序法对极化活性区调节序列ZRS进行分析.结果 在该家系3代13人中,共有PPD患者4例,表现为不同程度的肢端畸形,家系中女性患者存在三指节拇指及并指多指,而男性患者存在并指多指,无三指节拇指.4例患者中仅有一例患者存在足部受累.系谱中每一代均有患者,男女均可患病.家系中所有患者ZRS上均存在105位置C>G改变,2名正常家庭成员未见该突变.结论 该指(趾)畸形为常染色体显性遗传病,家系患者间存在明显的表型差异.ZRS上105位置C>G的突变是该家系的致病原因.

一个Ⅱ型轴前多指家系的基因突变检测

目的 检测1个Ⅱ型轴前多指家系的基因突变.方法 收集先证者及其家系成员的临床资料及外周血样本.用试剂盒提取基因组DNA,用PCR扩增SHH基因的调控元件“极化活性区调控序列”(zone of polarizing activity regulatory sequence,ZRS),对PCR产物进行双向Sanger测序,以确定致病突变位点.结果 该家系表现为典型的Ⅱ型轴前多指.基因检测结果提示家系中患者均携带ZRS第105位的C>G杂合突变,在家系的正常成员及100例正常对照中均未发现相同的突变.结论 SHH基因调控元件ZRS内第105位C>G杂合突变是该家系的致病原因.

两个三指节拇指轴前多指家系的ZRS突变分析

目的明确两个中国汉族具有三指节拇指特征的轴前多指家系的致病突变。方法知情同意下采集家系1的9名家系成员（患者2例）、家系2的14名家系成员（患者7例）的外周血，提取基因组DNA；应用实时定量PCR与PCR-Sanger测序，对SHH基因的调控元件“极化活性区调控序列”（zone of polarizing activity regulatory sequence，ZRS）分别进行拷贝数与序列突变检测；应用变性聚丙烯酰胺凝胶电泳，检测家系1ZRS附近短串联重复序列的基因型，结合Sanger测序发现的点突变，进行单倍型分析。结果定量PCR显示两家系患者在ZRS区域均不存在拷贝数改变。Sanger测序结果显示，家系1的2例患者均存在ZRS406A〉G杂合突变、家系2的7例患者均存在ZRS105C〉G杂合突变，且突变在各自家系中均与多指表型共分离，在200名正常对照中均未检测到上述突变。已有报道ZRS的105C〉G杂合突变可引起典型的三指节拇指轴前多指；而ZRS的406A〉G杂合突变仅见于1个胫骨发育不良伴多指（趾）家系中。单倍型分析及测序结果提示，家系1中第1例出现肢端畸形的患者为ZRS406A〉G杂合突变的体细胞及生殖细胞嵌合体。结论SHH基因调控元件ZRs的406A〉G与105C〉G杂合突变分别为两个中国汉族三指节拇指轴前多指家系的致病突变。

Apical ectodermal ridge regulates three principal axes of the developing limb

Understanding limb development not only gives insights into the outgrowth and differentiation of the limb,but also has clinical relevance.Limb development begins with two paired limb buds(forelimb and hindlimb buds),which are initially undifferentiated mesenchymal cells tipped with a thickening of the ectoderm,termed the apical ectodermal ridge(AER).As a transitional embryonic structure,the AER undergoes four stages and contributes to multiple axes of limb development through the coordination of signalling centres,feedback loops,and other cell ac-tivities by secretory signalling and the activation of gene expression.Within the scope of proximodistal pattering,it is understood that while fibroblast growth factors(FGFs)function sequentially over time as primary components of the AER signalling process,there is still no consensus on models that would explain proximodistal patterning itself.In anteroposterior pattermning,the AER has a dual-direction regulation by which it promotes the sonic hedgehog(Shh)gene expression in the zone of polarizing activity(ZPA)for proliferation,and inhibits Shh expression in the anterior mesenchyme.In dorsoventral patterming,the AER activates Engrailed-1(En1)expression,and thus represses Wnt family member 7a(Wnt7a)expression in the ventral ectoderm by the expression of Fgfs,Sp6/8,and bone morpho-genetic protein(Bmp)genes.The AER also plays a vital role in shaping the individual digits,since levels of Fgf4/8 and Bmps expressed in the AER affect digit patterning by controlling apoptosis.In summary,the knowledge of crosstalk within AER among the three main axes is essential to understand limb growth and pattern fomation,as the development of its areas proceeds simultaneously.

Activated pyrolysed bacterial cellulose as electrodes for supercapacitors

In this paper, the bacterial celluloses(BCs) were pyrolysed in nitrogen and then activated by KOH to form a porous three- dimension-network electrode material for supercapacitor applications. Activated pyrolysed bacterial cellulose(APBC) samples with enlarged specific surface area and enhanced specific capacitances were obtained. In order to optimize electrochemical properties, APBC samples with different alkali-to-carbon ratios of 1, 2 and 3 were tested in two electrodes symmetrical capacitors. The optimized APBC sample holds the highest specific capacitance of 241.8 F/g, and the energy density of which is 5 times higher than that of PBC even at a current density of 5 A/g. This work presents a successful practice of preparing electrode material from environment-friendly biomass, bacterial cellulose.

Octahedral PtNi nanoparticles with controlled surface structure and composition for oxygen reduction reaction

Controlling the surface structure and composi- tion at the atomic level is an effective way to tune the cat- alytic properties of bimetallic catalysts. Herein, we demon- strate a generalized strategy to synthesize highly monodis- perse, surfactant-free octahedral PtxNi1-x nanoparticles with tunable surface structure and composition. With increasing the Ni content in the bulk composition, the degree of concave- ness of the octahedral PtxNi1-x nanoparticles increases. We systematically studied the correlation between their surface structure/composition and their observed oxygen reduction activity. Electrochemical studies have shown that all the octa- hedral PtxNi1-x nanoparticles exhibit enhanced oxygen reduc- tion activity relative to the state-of-the-art commercial Pt/C catalyst. More importantly, we find that the surface struc- ture and composition of the octahedral PtxNi1-x nanoparti- cles have significant effect on their oxygen reduction activ- ity. Among the studied PtxNi1-x nanoparticles, the octahedral PtlNi1 nauoparticles with slight concaveness in its （111） facet show the highest activity. At 0.90 V vs. RHE, the Pt mass and specific activity of the octahedral PhNil nanoparticles are 7.0 and 7.5-fold higher than that of commercial Pt/C catalyst, re- spectively. The present work not only provides a generalized strategy to synthesize highly monodisperse, surfactant-free octahedral PtxNi1-x nanoparticles with tunable surface struc- ture and composition, but also provides insights to the struc- ture-activity correlation.